1. Field of the Invention
The present invention relates to the firing and data transmission circuitry for wedge type gun breechblocks, and more particularly, to the make-break feature of such circuitry between the non-recoiling mass of the gun cradle and the gun breechblock.
2. Related Art
Modern combat tanks, such as the Abrams main battle tank produced in the United States, carry large 120 mm caliber guns which electronically fire cartridges. Such guns usually include a gun barrel that is seated in a non-recoiling cradle; a breech ring located at the breech end of said gun barrel, which recoils longitudinally with the axis of the barrel's bore; and held within that breech ring is a wedge-type breechblock, that counter-recoils transversely to the axis of the barrel's bore to provide clearance for reloading the gun. Conventionally, disposed in the wedge-type breechblock is an ignition transmission unit, which unit can be displaced axially, counter to the pressure of a spring, from a retracted position into an extended position from the face of the breechblock unit to contact the cartridge, and is electrically connected via an ignition line to a contact device, e.g. a fire control computer, electrically connected via circuitry disposed on the stationary cradle.
As just stated, wedge-type breechblocks are conventionally designed to traverse longitudinally in a rearward direction with the recoil of the gun upon firing and to use that momentum to continue longitudinally rearwards, so as to space the breech mechanism away from the fixed cradle or non-recoiling mass. As the wedge-type breechblock returns to its in-battery position, against the cradle during counter-recoil, it also moves downward, transversely, to clear the gun tube for reloading. Finally, after the gun is reloaded, the breechblock snaps vertically, so that the face plate thereof is aligned with the loaded cartridge. Considering the fact that wedge-type breechblocks are experiencing such bi-directional motion, conventionally the ignition circuitry has been designed with two make-breaks to interface the circuitry from the stationary cradle structure into the wedge-type breechblock. The first “longitudinal” make-break is located so as to complete its contact when the wedge-type breechblock is in-battery, having completed its longitudinal motion back against the cradle after counter-recoil. The second “transverse” make-break is located so as to complete its contact when the wedge-type breechblock has completed its transverse motion and is back in alignment with the bore, and cartridge.
U.S. Pat. No. 6,543,330, incorporated herein by reference, discloses combination circuitry in which an ignition contact is disposed against the cartridge bottom for producing a connection to an external current source, and a signal contact is disposed against a connection ring also on the cartridge bottom, connecting to an external electronic control and evaluation device. However, the disclosed combination circuitry continues to use the conventional longitudinal and transverse sets of make-breaks of the prior art.
While U.S. Pat. No. 6,543,330 does simplify the circuitry within wedge-type breechblocks by combining ignition and signal transmission circuitry, it still utilizes a complex system of two sets of make-breaks, longitudinal and transverse make-breaks, to connect the circuitry from the stationary cradle to breechblock. Thus there is a need in the art for a simpler make-break system that utilizes only a single make-break, thereby reducing cost and creating a much more reliable electronic system, i.e. by eliminating half of the contacts which may fail if blocked by any foreign, insulating, matter.